2. MADDOX ROD
• MADDOX ROD CONSISTS OF A SERIES OF PLANO CYLINDER
LENSES ABOUT 3 MM IN DIAMETER, MOUNTED IN A TRIAL
FRAME LENS OR IN A REFRACTOR HEAD
• A SPOT OF LIGHT VIEWED THROUGH THE MADDOX ROD
APPEARS AS AN ELONGATED STREAK
• THE MADDOX ROD IS OFTEN COLORED USUALLY RED.
3. • THE TEST IS BASED ON THE PRINCIPLE OF DIPLOPIC PROJECTION.
• DISSOCIATION OF THE DEVIATION IS BROUGHT BY PRESENTING A RED LINE IMAGE TO ONE
EYE AND A WHITE LIGHT TO THE OTHER, WHILE PRISMS ARE USED TO SUPERIMPOSE
THESE AND EFFECTIVELY MEASURE THE ANGLE OF DEVIATION (HORIZONTAL AND
VERTICAL).
• THE STRENGTH OF THE PRISM IS INCREASED UNTIL THE STREAK OF THE LIGHT PASSES
THROUGH THE CENTRE OF THE PRISM, AS THE STRENGTH OF THE PRISM INDICATE THE
AMOUNT OF THE DEVIATION PRESENT
4. USES
• USED TO FIND OUT PRESENCE OF HETEROPHORIA OR
HETEROTROPIA
• EASY FOR PATIENT TO UNDERSTAND
• EASY TO ADMINISTER
• VERY USEFUL FOR VERTICAL DEVIATIONS
5. MADDOX ROD TEST
• EQUIPMENT REQUIRED ARE
1. MADDOX ROD
2. SMALL FIXATION LIGHT
3.PRISMS ( TO ASSES THE DEGREE OF DEVIATION )
6. PROCEDURE
• REDUCE ROOM ILLUMINATION.
• MADDOX ROD IS PLACED IN FRONT OF ONE EYE
• MEASURING HORIZONTAL DEVIATIONS MADDOX ROD AXES ARE PLACED
HORIZONTAL WHICH PRODUCES VERTICAL STREAK
• MEASURING VERTICAL DEVIATIONS MADDOX ROD AXES ARE PLACED VERTICAL
WHICH PRODUCES HORIZONTAL STREAK
• PATIENT INITIALLY VIEWS WITH BOTH EYES OPEN
7. METHOD OF ASSESMENT
• THE METHOD OF ASSESSING NEAR AND DISTANCE FIXATION IS
SIMILAR.
•
• A) ESODEVIATION, B) EXODEVIATION, C) HYPO-DEVIATION, D) HYPER-DEVIATION, E) NO DEVIATION
8. FOR HORIZONTAL DEVIATION
• WHEN PERFORMING THE CLINICAL TEST, THE ROOM LIGHTS SHOULD BE
DIMMED AND ONLY ONE LIGHT SOURCE SHOULD BE VISIBLE.
• WHEN TESTING AT NEAR, THE PATIENT IS TO FIXATE ON LIGHT SOURCE AT
33 CM, WHICH IS HELD AT EYE LEVEL. WHEN TESTING AT DISTANCE, THE
PATIENT IS TO FIXATE ON A LIGHT SOURCE AT 6M.
• PATIENT IS INSTRUCTED TO FIXATE ON THE LIGHT SOURCE WITH BOTH
EYES OPENED.
• THE MADDOX ROD IS THEN PLACED OVER THE FIXATING EYE.
9. • TO MEASURE THE HORIZONTAL DEVIATION, THE MADDOX ROD IS PLACED IN FRONT OF THE
RIGHT EYE (IT IS DONE ON BOTH EYES) WITH THE CYLINDER HORIZONTAL, MAKING THE RED
LINE VERTICAL. THE PATIENT IS THEN ASKED WHETHER THE WHITE LIGHT IS SUPERIMPOSED
ON THE RED LINE, OR IF IT IS TO THE LEFT OR RIGHT OF THE RED LINE.
• IF THE PATIENT SAW A RED LINE TO THE RIGHT AND WHITE LIGHT TO THE LEFT, THEY ARE
SAID TO HAVE ESOTROPIA OR ESOPHORIA (UNCROSSED DIPLOPIA) IN WHICH BASE OUT (BO)
PRISMS OF INCREASING STRENGTH ARE USED UNTIL THE LINES ARE SUPERIMPOSED.
• IF THE PATIENT SAW A RED LINE TO THE LEFT AND WHITE LIGHT TO THE RIGHT, THEY ARE
SAID TO HAVE EXOTROPIA OR EXOPHORIA (CROSSED DIPLOPIA) IN WHICH BASE IN(BI)
PRISMS OF INCREASING STRENGTH ARE USED UNTIL THE LINES ARE SUPERIMPOSED.
10. FOR VERTICAL DEVIATIONS
1. THE MADDOX ROD IS HELD IN FRONT OF THE PATIENT’S RIGHT EYE WITH THE
CYLINDERS VERTICAL, MAKING THE RED LINE HORIZONTAL.
THE PATIENT IS THEN ASKED WHETHER THE WHITE LIGHT IS SUPERIMPOSED ON THE
RED LINE OR IF IT APPEARS ABOVE OR BELOW THE RED LINE.
IF THE LINE APPEARS BELOW THE LIGHT, THERE WILL BE A HYPER-DEVIATION IN WHICH
BASE DOWN PRISMS ARE USED TO MEASURE AND CORRECT THE DEVIATION.
IF THE LINE APPEARS ABOVE THE LIGHT, THERE WILL BE A HYPO-DEVIATION AND BASE
UP PRISMS ARE USED MEASURE AND CORRECT THE DEVIATION.
IF THE WHITE LIGHT IS SUPERIMPOSED ON THE RED LINE, THERE ARE NO VERTICAL
DEVIATIONS PRESENT
11. RECORDING
• EXAMPLES OF RECORDINGS ARE SHOWN BELOW:
• MR: SC (F) L/R 5∆ ESO 8∆ (FR)
• MR: SC (F) L/5∆ ESO 8∆ (FR
• MR: SC (F) 5∆ BD 8∆BO (FR)
• SC: WITHOUT CORRECTION
• - F: FAR;- N: NEAR
• - FR: FIXING RIGHT;- FL: FIXING LEFT
• - BD: BASE DOWN PRISMS;- BU: BASE UP PRISMS
• - BO: BASE OUT PRISMS-; BI: BASE IN PRISMS
• - ESO: ESOTROPIA; EXO: EXOTROPIAS
• - L/R: LEFT HYPERTROPIA OR RIGHT HYPOTROPIA
12. DOUBLE MADDOX ROD
• THE DOUBLE MADDOX ROD TEST CAN ALSO BE USED TO ASSESS
TORSION AND MEASURE CYCLOTROPIAS
13. • THE ROOM LIGHTS SHOULD BE DIMMED AND ONLY ONE LIGHT SOURCE
SHOULD BE VISIBLE
• MADDOX RODS ARE PLACED INTO THE TRIAL FRAMES, ONE BEFORE EACH
EYE
• CYLINDERS ARE PLACED INTO TRIAL FRAME VERTICALLY, MAKING THE TWO
RED LINES HORIZONTAL
• VERTICAL PRISM ( BASE-UP, OR BASE-DOWN) CAN ALSO BE ADDED INTO THE
TRIAL FRAMES TO SEPARATE THE TWO RED LINES (THIS AVOIDS CONFUSION
IF THE PATIENTS CLAIM THAT THEY ONLY SEE ONE RED LINE). THE DEGREE
OF DEVIATION AND THE DIRECTION (INCYCLO OR EXCYCLO) CAN BE
DETERMINED BY THE ANGLE OF ROTATION THAT CAUSES THE LINE IMAGES
TO APPEAR HORIZONTAL AND PARALLEL.
14. • THE AMOUNT OF CYCLODEVIATION IS MEASURED IN DEGREES, UTILISED
FROM THE SCALE ON THE TRIAL FRAME
• WHEN TESTING AT NEAR, THE PATIENT ASKED TO FIXATE ON LIGHT SOURCE
AT 33 CM, WHICH IS HELD AT EYE LEVEL. WHEN TESTING AT DISTANCE, THE
PATIENT IS TO FIXATE ON A LIGHT SOURCE AT 6M.
• PATIENT IS INSTRUCTED TO FIXATE ON THE LIGHT SOURCE WITH BOTH EYES
OPENED
• PATIENT IS ASKED TO ROTATE OR THE EXAMINER ROTATES THE CYLINDERS
WITH THE AXIS KNOB ON THE TRIAL FRAME UNTIL THE 2 RED LINES ARE
PARALLEL
• THIS TEST CAN BE REPEATED FOR THE SECONDARY AND TERTIARY
POSITIONS OF GAZE
15.
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17.
18. ADVANTAGES
• CAN EASILY BE PERFORMED
• SIMPLE AND FAST TECHNIQUE
• CAN BE USED ON CHILDREN, IF THEY CAN RESPOND RELIABLY
• CAN BE USED TO TEST EYE MUSCLE
